The present invention relates to a method of forming air bridges on electronic devices. The method uses amorphous silicon carbide to protect the conductors on the device during and after the air bridge formation.
The electronics industry continues to strive to decrease the size of devices. One of the difficulties in the process of miniaturization is maintaining a sufficient dielectric between conductors to prevent device failure.
To solve this problem, the industry has investigated a wide variety of low dielectric constant materials. These materials have shown to provide dielectric constants of about 2 and above. Unfortunately, many of these materials are difficult to process and their chemical and physical properties can be incompatible with the devices.
One of the best dielectrics available is simply air. Various investigators have attempted to capitalize on this by leaving voids between adjacent conductors. These voids are often called "air bridges". For instance, Fitch et al. in U.S. Pat. No. 5,324,683 describe the formation of an air bridge in an integrated circuit by removing all or a portion of a dielectric layer between conductors. The methods, materials and final product described therein, however, are different than those of the present invention.
The present invention has now discovered a method for forming an air bridge which uses the properties of silicon carbide in its formation and has the unexpected advantage of being more durable after formation.